The Invasion of Normandy, sometimes known as Operation Overlord or simply D-Day, was a World War II military operation that involved the Allied invasion of western Europe. Beginning on June 6, 1944, a combination of American, British, and Canadian forces coordinated five distinct assaults along beaches in Northern France. The invasion is considered one, if not the, most pivotal turning points of the war. By August of 1944, Allied forces had liberated the entirety of Northern France from Axis control, and would use this new position to begin the move into Germany.
Planning for the event began as early as 1942, when premier Joseph Stalin urged President Franklin D. Roosevelt and Prime Minister Winston Churchill to stage a second front against Axis powers in the West. However, both nations lacked the resources and manpower to do so. Ultimately, Allied forces were able to assemble more than 13,000 fighter, bomber, and transport aircraft to support the 3,000 landing craft, 2,500 ships, and 500 naval vessels. All told, the Invasion of Normandy involved approximately 156,000 Allied troops on the first day, a number that rose to nearly 327,000 by June 11, making it the largest amphibious military invasion in world history.